External inflatable drop stitch stability system for boats

ABSTRACT

An inflatable stability and fender system including high pressure drop stitch D-shaped tubes mounted on a hard sided monohull of a boat or on the side of a dock by extrusions, thru bolting and boat ropes for sealing engagement with the monohull of the boat or the dock.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/754,480 filed Jan. 18, 2013, the contents of which are incorporated herein by reference.

BACKGROUND

Small watercraft, especially outboard powered boats, are used for fishing, motoring, waterskiing and recreational boating. Some are inflatable boats with round shaped air tubes or RIB's, hard sided boats with round air tubes or expensive tubes built with a combination of foam and air bladders. Inflatable boats offer increased stability and buoyancy over a conventional monohull boat, but result in higher cost and a higher degree of complexity to manufacture. The round shaped air tube takes up interior space and requires complicated tooling to cradle the tube as well as complicated attachment to the boat by gluing or bolting systems. These inflatable boats or RIB's are an original design and are not available as an aftermarket kit to convert existing hard sided boats to take advantage of increased stability and buoyancy. The United States Coast Guard regulations for monohull outboard boats under 20 feet in length and rated for more than 2 horsepower must comply with a more sophisticated flotation system called level flotation.

Modified or deep V monohull boats have a hump characteristic which requires larger motors to achieve planing. Larger motors are problematic in that they are more expensive to operate and are quite heavy for smaller boats. Another problem with smaller monohull boats is the instability created when a passenger is loaded or unloaded in to or out of the boat, or during movement within the boat. Such instability can lead to a passenger falling out of the boat and drowning. Consequently, a need exists for an inflatable stability system for hard sided monohull boats which is inexpensive, lightweight and easy to manufacture which improves the stability of the boat when passengers are boarding, unloading, or moving within the boat.

SUMMARY OF THE INVENTION

The present invention is directed to an external inflatable drop stitch stability system for hard sided monohull boats which includes a pair of high pressure drop stitch D-shaped tubes mountable along the side of the boat by extrusions that are attached by thru bolting to the boat. The D-shaped tubes are secured by the insertion of two bolt ropes into the extrusions and inflating the D tubes for a seal to the sides of the hull. An optional pointed nose cone covers the bow end of the inflatable tube to lock the system in place and deflects water from entering the front of the stability system. The nose cone also stops deflection of the tube and maintains strength and rigidity. The stability systems allows for easy removal or replacement. The D tubes when used as a stability system are mounted with the aft end several inches above the water line when the boat is at rest without passengers. Alternatively, the D tubes can be positioned at or a few inches below the water line. The D tubes are mounted just ahead of the transom and extend along the length of the boat. An air fill valve is mounted on the top of the inflatable D tube.

Another aspect of the invention is that the inflatable drop stitch stability system can be installed along docks or seawalls as a fender system only for both boats and docks. A coupler can attach multiple D tubes together end to end to form the fender system. The fender system would be attached to a side wall of the docks or seawall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a boat incorporating an external inflatable drop stitch stability system of the present invention;

FIG. 2 is perspective view of the D-shaped tubes of the stability system of FIG. 1;

FIG. 3 is a perspective view of a coupler for adjoining adjacent D-shaped tubes; and

FIG. 4 is a perspective view of the stability system as a fender system for a dock.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate the external inflatable drop stitch stability system 10 for boats 12 of the present invention. The stability system 10 includes a pair of high pressure drop stitch D-shaped tubes 14 (only one is shown) mounted on either side 16 of a monohull boat 12 by aluminum, plastic or stainless steel extrusions 18 that are attached by thru bolts 20 into the side of the boat. The D-tubes are secured by the insertion of two bolt ropes 22 extending into the extrusions. FIG. 1 depicts the extrusions, bolts and bolt ropes along the top of the D tube, however a second set of extrusions, thru bolts and bolt rope would be positioned along a bottom surface of the D tube which is obscured by the water line. An air fill valve 24 is positioned on an upper surface of the D tubes for inflation of the D tubes for a seal to the sides of the hull.

A nose cone 26 is positioned on the bow end of the D tube to lock the system in place and deflect water from entering the front of the D tube stability system. The nose cone also stops deflection of the D-tube and maintains strength and rigidity. The D tubes are mounted with the aft end several inches above the water line when the boat is at rest without passengers. Alternatively, the D tubes can be mounted at or slightly below the water line. The D tubes are mounted just ahead of the transom and have a length of about 40% to about 60% of the water line length. The air flow valve is mounted on the top of the inflatable tube and preferably located at 50% of the overall length so that the tube can be mounted on either the port or starboard side and have the fill valve located at the same distance from the transom.

The D tubes are manufactured from high pressure drop stitch material having a construction which refers to upper and lower fabric layers and also a core section made up of an array of threads extending throughout the drop stitch structure. A benefit of this material is that the inflated walls of the material create rectangular shapes of varying lengths, widths and depths, instead of taking on a rounded “balloon” shape. Consequently, the use of high pressure drop stitch material allows the tubes to be manufactured in a D-shaped configuration which is ideal for use on hard sided monohull boats. The stability system of the present invention provides an aftermarket solution for increased stability and buoyancy for monohull boats. The stability system is ideal for monohull outboard boats under 20 feet in length and rated for more than 2 horsepower. The stability system meets the sophisticated floatation requirements implemented by United States Coast Guard regulations.

Modified or deep V monohull boats have a hump characteristic which requires larger motors to achieve planing. The present invention allows for the use of smaller and lighter, less costly engines, which use less fuel to achieve similar performance. The present invention improves the safety of any monohull boat it is added to. Using lighter engines with less fuel improves the balance of the boat. The stability system also improves stability when people are boarding or are loaded with more weight to one side than with normal seating, a common occurrence when fishing or other recreational sports.

As shown in FIGS. 2 and 3 for applications requiring a number of tubes 14, a coupler 28 can be utilized to connect individual sections of tubes together end to end. The coupler 28 is also D shaped and has an internal configuration 30 sized to accept the exterior configuration of the D tubes. In certain circumstances, the coupler 28 also can have an air fill valve 32 for inflation of the tubes.

As shown in FIG. 4, the invention can also be used as a fender system 34 for docks or seawalls 36. The fender system 34 would include a plurality of high pressure drop stitch D tubes 14 connected by connectors 28 and attached to a vertical wall 38 of the dock or seawall. The D tubes would be attached to the vertical wall 38 similar to the attachment method to the side of the boat hole; however, other attachment mechanisms can be utilitzed.

The present invention has been described and illustrated with various embodiments thereof, however changes and, modifications can be made therein which are within the full intended scope of the invention. Changes or alterations could include plastic or other material for the attachment extrusions for receipt of the thru bolting. Other attachment mechanisms can be utilized besides extrusions and thru bolting such as adhesives, rivets, or other attachment mechanisms well known in the art. Example dimensions for the D tubes could include 6″ to 8″ wide, 6″ to 18″ high and 5′ to 18′ long. However, the exact size and dimension for the D tubes will depend upon the specific boat for which it is utilized as a stability system, or for a fendering system depending upon the particular application. The invention contemplates the use of D tubes with the optional coupler, or manufactured in custom lengths which would not require couplers.

The present invention provides improved lateral and longitudinal hull stability while at rest and in motion. The stability system increases buoyancy and load capacity and is a solution for level flotation compliance. The stability system of the present invention is an external solution and provides no sacrifice of interior space within the vessel. The present invention can be utilized as a permanent fendering for hull protection or for docks, hoists and walls. The present invention enhances performance, saves fuel and reduces operating costs. 

What is claimed is:
 1. A stability system for a monohull boat comprising: a pair of inflatable D-shaped drop stitch tubes; an air fill valve positioned along the length of the tube; and means for attaching one of the inflatable D-shaped drop stitch tubes on either side of the monohull boat.
 2. The system of claim 1 wherein the means of the attaching the tubes are a plurality of boat rope extensions and rope.
 3. The stability system of claim 1 further comprising a coupler for connecting a plurality of D-shaped drop stitch tubes end to end.
 4. The stability system of claim 1 wherein the system further comprises a nose cone positioned on an end of each tube.
 5. A fendering system for a dock comprising: an inflatable D-shaped drop stitch tube; an air fill valve positioned along the length of the tube; and means for attaching the tube to the dock.
 6. The fender system of claim 5 wherein the means of attaching the tube to the dock include a plurality of bolt rope extensions and a rope.
 7. The fender system of claim 5 wherein the inflatable D-shaped drop stitch tube includes a plurality of sections connected end to end by a coupler.
 8. A boat comprising: a V-shaped hard sided monohull; an inflatable drop stitch D-shaped tube mounted on either side of the monohull; an air fill valve positioned along a top surface of each tube; and an attachment mechanism positioned along the length of the tube for connecting the tube to each side of the monohull.
 9. The boat of claim 8 wherein the attachment mechanism is a plurality of boat rope extensions and rope.
 10. The boat of claim 8 further comprising a coupler for connecting a plurality of D-shaped drop stitch tubes end to end.
 11. The boat of claim 8 further comprising a nose cone positioned on an end of each tube. 